Developing write-sharing applications is challenging. Remote and offline data sharing are increasingly important. We propose a generic platform called Telex to ease development and to provide guarantees. Telex is driven by application semantics. Telex takes care of replication and persistence, drives application progress, and ensures that replicas eventually agree on a correct, common state. We show by example how application design proceeds from high-level application invariants to application-provided parameters that guides Telex. The main data structure of Telex is a large, replicated, highly dynamic graph; we discuss the engineering trade-offs for such a graph and our solutions. Finally, we report an experimental evaluation of Telex based on a cooperative calendar application and on benchmarks.